The present invention relates to a laser surveying system for projecting laser beams by rotary irradiation and for performing measurement on an object to be measured.
A type of laser surveying system is already known, which performs a distance measurement by projecting a distance measuring light by rotary irradiation, and detects horizontal angle and elevation angle by projecting two or more fan-shaped laser beams with at least one of the beams tilted by rotary irradiation, and measures three-dimensional data.
The laser surveying system as described above comprises a measuring device and a photodetection device. The measuring device projects distance measuring light and fan-shaped laser beams by rotary irradiation, measures a distance to the object to be measured by receiving reflected distance measuring light from the object to be measured, also obtains horizontal angle at the moment of photodetection, and transmits the result of measurement to the photodetection device.
The photodetection device as described above receives two or more fan-shaped laser beams and obtains elevation angle at photodetecting position of the photodetection device based on the difference of photodetection time when the fan-shaped laser beams are received and also based on tilt angles of the fan-shaped laser beams. Further, based on the elevation angle thus obtained and based on the result of the measurement transmitted from the measuring device, the photodetection device acquires horizontal angle, and acquires three-dimensional data on the photodetection device by calculating a height based on the result of distance measurement and the elevation angle.
Or, by transmitting the elevation angle from the photodetection device to the measuring device, and three-dimensional data of the photodetection device were calculated at the measuring device.
The laser surveying system as described above is disclosed in JP-A-2006-337302.
In the laser surveying system as given above, it is necessary to have a photodetection unit for detecting fan-shaped laser beams as an object to be measured and a photodetection device provided with an arithmetic unit, which calculates elevation angle based on the results of photodetection. Also, it is necessary to have communication means for transmitting and receiving the results of calculation or the like to and from the measuring device and the photodetection device.
As a result, the arrangement of the system is complicated and costly.
JP-A-2006-337302 discloses a measuring device, which projects fan-shaped laser beams in N-shaped form by rotary irradiation, projects distance measuring light by rotary irradiation, and measures a distance to the object to be measured by receiving reflection light from the object to be measured. In this measuring device, when the distance measuring light is projected by rotary irradiation, distance measurement can be performed on two or more objects to be measured at the same time. Therefore, based on the measured elevation angle and the measured distance, a position of direction of height with respect to the object to be measured, i.e. the object to be measured, can be measured.